Star Trek: The Next Generation
Williams, 1993My flashers aren't working, I figured out that tp7 (which should be 20v) and the related test LED are dead.
I believe I need to replace BR4 and C11.
Does that sound right?
I've never tackled board repairs before, I'm a little nervous about it. Any basic advice?
Thanks!!!!!!!
thanks for the advice!
Yeah, checked fuses first. No power going to fuse F111.
did not check J102 (not sure where that is, actually)
I will test the BR next, thanks for posting the video.
I did check all the other test points, so the problem seems to be isolated to the 20v circuit.
This is my first pin, so a lot of this is pretty new to me.
You probably need to replace the bride rectifiers and caps, so you're probably right. My flashers weren't working either. You can take out the board and measure the BR4 with a multimeter.
Best thing to do it replace all caps and BR's in one swoop, there's replacement kits available I think.
Ive done this lately, if you like soldering, it's a nice zen job of maybe an hour work.
2014-01-30 18.51.53.jpg
Hrmmm...
So there are two white wires with a red stripe (I imagine one is going to J102??) on the interlock switch.
One is reading 18.5-19.5 volts, the other one isn't getting power when I depress the switch.
Would this indicate my interlock switch is bad?
(boy, I hope so!)
Thanks!!!!
Best not to replace BRs and caps unless you have really good evidence that they are bad.
You can easily bypass the interlock with a jumper of some sort for test purposes. It is a safety interlock, so it needs to go back together properly. Just beware of the 50VAC solenoid supply that also sits on the interlock switch.
zaza- I measured across the wires at the interlock (not the j102 pins) and measured them seperately. No voltage between them, but one wire was reading 18v or so.
I didn't want to mess around without making sure how the switch is wired (there are 4 wires on the switch), I'll run a jumper between the wires at the switch and see what happens when I get home tonight.
If it IS the BRs and caps, I'll have a pro do it.
Thanks again, everyone!!!
Quoted from FreeBee:...
Best thing to do it replace all caps and BR's in one swoop, there's replacement kits available I think...
Oyyy. Please don't do this. It's never a good idea to replace the caps and bridges in one swoop, NEVER!!!!! If it ain't broke, don't fix it.
Fix what's bad, don't fix what's not. If you're not capable of determining what's bad, then hand it off to someone who is.
--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com
I must have made a mistake, can't read any voltage coming to either side of interlock switch (also checked resistance, switch is working).
Also double checked both sides of fuse F111 and the pins on J102. All reading less than a volt (but more that zero)
So, it's pretty clear that it's probably the related BR4 and C11, no?
I haven't pulled the power board to test the BR.
Finally, just to check that I'm not an idiot, these are tested from the ground strap in the back box? All other test points read correctly when tested across ground strap.
Thanks!
Quoted from FreeBee:You probably need to replace the bride rectifiers and caps, so you're probably right. My flashers weren't working either. You can take out the board and measure the BR4 with a multimeter.
Best thing to do it replace all caps and BR's in one swoop, there's replacement kits available I think.
Ive done this lately, if you like soldering, it's a nice zen job of maybe an hour work.2014-01-30 18.51.53.jpg 625 KB
Really, really bad advice. I've fixed a LOT of boards where someone got this idea, and one problem turned into a bunch when they damaged some traces / vias.
Oh for F**K's sake!!!!
Was getting a false reading across fuse F111, it was blown, but I was getting some continuity through it??? (WTF??)
I've had a bad meter before, maybe this one is failing.
So, let's start over.
Fuse F111 is blowing. Replaced it and it blows immediately.
All other test points are reading correctly. I AM getting 16v across the pins on J102, and I AM getting 16v to one side of fuse F111.
What gives?
I'm guessing this points to bad BR and capacitor?
I borrowed a different meter, verified everything in my last post. My meter is going in the garbage!
I did replace a bunch of flasher bulbs recently, but they've been working for at least two weeks. I suppose it's possible I have a short in one of the flasher sockets???? What's the best way to check that?
Side note- This is my first table, I've had it about a month now. Seeing enthusiastic home use after sitting dormant for a while. It was refurbished in 2001, hasn't been touched since then (and I don't think it was used much in the past five years). I'm not entirely surprised some gremlins are popping up, I've had the glass off and the playfield up almost daily.
Thanks!!!!
Remove all connectors from the bottom of the driver board except J116, J117, and J118. Does the fuse still blow? If yes, the bridge is likely shorted, cap is likely fine. If no, you likely have a shorted flasher or socket.
--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com
Follow Robs advice above; he's the man.
A similar thing happen to my TOM. I replaced a flasher bulb and the socket has two tabs, and one of them spun around and shorted the other leg. It shorted, blew the fuse and shorted the transistor. Simple fix once I found the culprit, but it took a bit of inspection and a board repair.
Marc
Quoted from Borygard:Remove all connectors from the bottom of the driver board except J116, J117, and J118. Does the fuse still blow? If yes, the bridge is likely shorted, cap is likely fine. If no, you likely have a shorted flasher or socket.
--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com
Did this, the fuse still blew.
Getting some pro help lined up, thanks for the advice!
20Volt exit at J106 and J107 should have been disconnected as well.
If this red-white wire is somewhere shorted with ground, then the fuse will blow as well.
If manual is correct, this wire is used in J106-5 and J107-6
When disconnected, together with J122-J126, it is possible to test for short with ground.
Been reading this thread hoping it would send me in the right direction as well. My problem is all the bulbs blow when I put them in as if all the transistors are locked on (but they test fine.) I have verified that the Bridge 3 and 4 are not shorted out, the capacitor at c8 takes a charge and also discharges it. The voltage is 72V at the test point for 50V. The only strange things are that led number 5 is not lit. When I put a bulb in the back box it also cycles a coil on the playfield. Any ideas?
Interesting.
During this process, I found that there were 5 or 6 empty sockets (regular bulbs, not flashers) on the back board, mostly behind Data's head. I put new bulbs in there, and they now light up fine.
Now I'm getting a ball cycling, I assumed it was a problem with the opto board in the trough, but it could be caused by the diverter coil cycling.
A few days before all the trouble, I also had to replace one of the diverter coils in the subway- now I'm assuming that it may all be related? The coil melted the sleeve, I (probably incorrectly) figured that the coil was just bad.
Maybe I do have a weird short somewhere????
Honestly, I don't think I'll turn it on again, JR from Pinball Plus is coming to take a look.
I'm trying to piece this all together and understand what's going on. If a fuse blows (and/or a br is shorted), could that have locked up a coil circuit and fried it? Or is it more likely that an opto is bad somewhere?
Wondering if I pull the balls out and out a new fuse in, might it have power long enough to reset everything so the coil isn't cycling???
Sorry if this is a dumb question, I'm still new to this.
Thanks!!!!
coz6 and big_ragu:
First thing to do is to check/re-seat all the data-cables, including the one going to the 8-driver (upper-right in backbox). Then check all powercables, again including the 8-driver.
co76:
just in case, measure TP7 for 20 Volts.
big_ragu:
coil melting the sleeve is most likely caused by bad data-cable to 8-driver, but clean all opto's under playfield.
Go into Switch-Edges-Test and check opto's while the interlock-door-switch is open so no coils/flasher can burn.
Quoted from big_ragu:Interesting.
During this process, I found that there were 5 or 6 empty sockets (regular bulbs, not flashers) on the back board, mostly behind Data's head. I put new bulbs in there, and they now light up fine.
Now I'm getting a ball cycling, I assumed it was a problem with the opto board in the trough, but it could be caused by the diverter coil cycling.
A few days before all the trouble, I also had to replace one of the diverter coils in the subway- now I'm assuming that it may all be related? The coil melted the sleeve, I (probably incorrectly) figured that the coil was just bad.
Maybe I do have a weird short somewhere????
Honestly, I don't think I'll turn it on again, JR from Pinball Plus is coming to take a look.
The only thing I can tell you is I have had the balls cycling on two WPC games, both happened when I was having issues with the Flash Lamps. The First time was a cord was hooked up wrong, and locking on a few of the flash lamps. The prior owner had removed the bulbs from the game to keep the issue from going on. Similar to your situation. The second time is going on now.
Quoted from zaza:coz6 and big_ragu:
First thing to do is to check/re-seat all the data-cables, including the one going to the 8-driver (upper-right in backbox). Then check all powercables, again including the 8-driver.
co76:
just in case, measure TP7 for 20 Volts.
big_ragu:
coil melting the sleeve is most likely caused by bad data-cable to 8-driver, but clean all opto's under playfield.
Go into Switch-Edges-Test and check opto's while the interlock-door-switch is open so no coils/flasher can burn.
I will measure TP7 for 20 Volts. Any Reason that LED5 is not on? I will also swap ribbon cables, since I have a working game to test them from. Thanks for the advice.
Quoted from zaza:There can be many reasons why LED 5 is not on, from no power to just a burnt resistor. R194 1.5K
I think its the Resistor - my second question would be what does LED5 imply has power. Just trying to understand schematics so that I can ask less and repair more!
Quoted from big_ragu:Now I'm getting a ball cycling, I assumed it was a problem with the opto board in the trough, but it could be caused by the diverter coil cycling.
A few days before all the trouble, I also had to replace one of the diverter coils in the subway- now I'm assuming that it may all be related? The coil melted the sleeve, I (probably incorrectly) figured that the coil was just bad.
I had this problem as well, I had two problems, the grey yellow wire had a small cut in it, as well as the ground (black) wire. Repaired both still had same problem. Happend to look up while cursing the machine out and noticed that I forgot to re connect all the molex connectors. So make sure you resoldered the coil correctly and check for loose/disconnected connectors that send power to the subway coils.
The balls will keep cycling if there are not two(I think) balls locked up in the subway.
yahoo!!!! I'm back in business.
It was indeed a short in BR4, and the ball cycling was due to a loose arm in the one of the subway diverters (it was allowing a ball to pass through when it shouldn't have been)
Thanks to everyone for the advice in this thread, and thanks to John Ross of Pinball Plus for coming over and fixing my board.
I can't recommend JR highly enough!!!
I just purchased an STTNG whose flashers do not work at all. Solenoids and general illumination work fine.
I've begun diagnosis based on what I've seen in this thread:
LED5 is unlit.
I've pulled fuse F111 and it tests fine with my DMM (.2 ohms).
I about .1V AC across pins 1 and 4 on J102, it's about the same from tp7 to ground. The coin door switches seem to work--when I open the door with the game powered on, I get the high voltage cutoff warning and beeping.
Testing across the 2 white/red wires at the closest connector to the transformer shows no AC voltage. It feels unlikely that the transformer itself is bad, but I'm no expert.
I have not pulled the board to test BR4 or C11 yet, since they don't seem to be indicated by what I've seen so far.
Help? More diagnostic advice? Thanks in advance!
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Anoka, MN